The Washington National Primate Research Center (WaNPRC) has supported AIDS-related research projects for more than 25 years. These projects are performed at the Western facility, where the vivarium is designed to house nonhuman primates at an ABSL-2 containment level with enhanced containment practices implemented for lentivirus research. The AIDS-related research program is expanding with the addition of new core staff, funding of new projects for existing core staff, and new collaborative efforts between core staff and external investigators. With a projected increase in animal numbers, a need to upgrade cage wash facilities, and a need to expand surgical capabilities for upcoming projects, the University of Washington has committed $5.6 million to expand the vivarium by approximately 2500 square feet at the WaNPRC Western facility, install a new cage-wash/autoclave facility and build a state-of-the-art surgical suite for the support of AIDS-related research. We are requesting additional funding to convert the current surgical area into animal housing and to build out additional area within the expanded vivarium space for animal holding. The proposed animal holding rooms will accommodate 80 Group four (10-15 kg) nonhuman primates, or more smaller animals. The rooms will be constructed in accordance with the recommendations of the eighth edition of the Guide for the Care and Use of Laboratory Animals. The completion of the animal holding space will synergistically complement the institutionally-funded project to upgrade the cage-wash facilities and surgical suite, and will improve and increase our ability to conduct biomedical research, especially AIDS-related research.